INTRAMOLECULAR CYCLIZATIONS OF ALPHA-LITHIOAMINE SYNTHETIC EQUIVALENTS - CONVENIENT SYNTHESES OF 3-MEMBERED-RING, 5-MEMBERED-RING, AND 6-MEMBERED-RING HETEROCYCLIC NITROGEN-COMPOUNDS AND ELABORATIONS OF 3-MEMBERED RING-SYSTEMS

A lithiation-intramolecular cyclization reaction of N-Boc chloroalkyl secondary amines is reported to provide the 2-aryl-substituted pyrroli dine and piperidines 6, 7, 9, and 11 and a series of 2-azabicyclo[3.1. 0] derivatives 14-25, including cyclopropane derivatives of proline an d of the indolizidine-pyrrolizidine alkaloid ring system. Lithiation-s ubstitutions of N-Boc-N-ethylcyclopropylamine to give 27-29 and lithia tion-silylations of N-Boc aziridines to give 31-33 also are reported.